1. Field of the Invention
The present invention relates to a structure for a lower part of a rear vehicle body including a spare tire housing formed in a rear floor of the rear vehicle body.
2. Description of Related Art
A typical vehicle includes a spare tire housing for housing a spare tire, in a rear floor of a rear vehicle body. When a load is applied to the vehicle with such a structure from the rear of the vehicle, the spare tire housing is sometimes deformed and moved toward the front of the vehicle. Since a fuel tank is arranged ahead of the spare tire housing in the vehicle, in particular, the deformed spare tire housing may come into contact with the fuel tank.
A conceivable countermeasure to such a case is to secure a distance between the spare tire housing and the fuel tank to let a space around the spare tire housing absorb the load.
Meanwhile, the distance between the spare tire housing and the fuel tank cannot be sufficiently secured in many cases because a space to house components other than the spare tire housing and the fuel tank also needs to be secured, and there are many restrictions in the layout of vehicle body components. Moreover, in the case of a compact car, it is difficult to secure sufficient space around the spare tire housing.
To cope with this, JP 10-316050 A (hereinafter Patent Document 1) discloses a structure in which a bottom surface of a spare tire housing is formed to be inclined obliquely, that is, to extend from its front side rearwardly downward to prevent the deformed spare tire housing from coming into contact with a rear differential device and a fuel tank. In addition, a reinforcement extending in a front-to-rear direction of a vehicle is arranged below the bottom surface of the spare tire housing, and a sloped guide surface is formed in the reinforcement. The sloped guide surface guides and helps the spare tire housing to ride over the rear differential device.
Accordingly, with the structure disclosed in Patent Document 1, the spare tire housing is deformed while being guided by the guide surface of the reinforcement toward above the rear differential device when a load is applied from the rear of the vehicle, which prevents the spare tire housing from interfering with the rear differential device and the fuel tank. Moreover, when the spare tire housing is deformed, the spare tire is rotated while moving its upper edge part rearward in the vehicle, which makes the spare tire less likely to come into contact with a backseat.
In the configuration in Patent Document 1, however, the reinforcement is provided to a lower surface of the spare tire housing, and therefore the spare tire housing has such a high surface rigidity that the spare tire housing is less likely to be deformed when a load is applied from the rear of the vehicle. This causes a problem that the load from the rear of the vehicle cannot be absorbed efficiently.
Furthermore, in the configuration in Patent Document 1, the guide surface of the reinforcement below the lower surface of the spare tire housing comes into contact with the rear differential device when the spare tire housing is deformed. For this reason, there is a problem that the load received from the rear of the vehicle is transmitted to structures arranged in the front, such as the rear differential device.